Office of Technology Transfer – University of Michigan

Server Idle Power Elimination

Technology #4184

Questions about this technology? Ask a Technology Manager

Download Printable PDF

Thomas Wenisch
Managed By
Joohee Kim
Licensing Specialist, Physical Sciences & Engineering 734-764-8202
Patent Protection
US Patent Pending


It is becoming more common for computers and other electronics to utilize low power quiescent modes during periods of inactivity. In particular, power consumed in a typical data center by servers is wasted by idle servers that are powered on, but not performing useful work. Several approaches, including certification, single voltage supplies, DC distribution, and dynamic load sharing are being explored currently to improve server power efficiency.


Researchers at the University of Michigan have developed a power management system and method for use with servers or other networked computers. The system provides two distinct modes of operation: Active Mode and PowerNap Mode. When the server becomes idle, it transitions to PowerNap Mode, where the server stays sedentary, consuming minimal power until work arrives. When work arrives, the server returns to Active Mode to resume normal operation. From the point of view of software executing on the server, this transition is seamless and appears as if the server was in Active Mode the entire time. The PowerNap mode supports low-latency sleep and wakeup transition. With this system, no single server component dominates power consumption. For this reason, PowerNap puts all main system components into a low power state whenever the server becomes idle, maximizing power savings.

Applications and Advantages


  • power management systems for computer servers


  • power savings maximized as all main system components go into a low power state whenever the server becomes idle